Pull shovel



April 7, 1936. p BURKE ET AL 2,036,680

PULL SHOVEL Filed Sept. 16, 1952 4 Sheets-Sheet l Jnnentov PM 83 M v attorney April 7, 1936. P. BURKE ET AL 2,036,680

7 FULL SHOVEL Filed Sept. 16, 1932 4 Sheets-Sheet 2 Ennentor @402 M Qttorneg April 7, 1936. p BURKE ET AL 2,036,680

PULL SHOVEL Filed Sept. 16, 1932 4 Sheets-Sheet 3 April 7, 1936. BURKE ET AL 2,036,680

I PULL SHOVEL Filed Sept. 16, 1932 4 Sheets-Sheet 4 a". an"

Ihwentor @we M y znw q 2 attorney Patented Apr. 7, 1936 UNITED STATES PATENT OFFICE PULL SHOVEL consin Application September 16, 1932, Serial No. 633,440

15 Claims. (Cl. 214-138) This invention relates to a novel form of excavating ..machine.. .whereimcontrolzof the movementof the same is greatly improved in a novel mannen It' is. the purpose of .this invention to arrange the elements. of an excavating machine, wherein a dipper and stick: assembly is pivoted to the boom, so.that;. relative movement of the dipper stick. assembly with respect .to the boom is restrained. in certain desired positions. It is the purpose of the machine of this invention to prevent destructive engagement of the parts of the machine and to do the same by employing the forces causing-engagement to produce the necessary restraint. It is a further purpose of this invention to cause the energy released upon restrainingzan engagement, to be absorbed by friction members capable of absorbing such-energy without the destruction thereof. A further purpose of this invention is to provide a machine with all of the above advantages and at the same time having equal range and facility of movement as compared with machines of a similar type formerly known;

In all excavators of the type here involved, the prevention of shock upon full extension of the dipper is a problem of importance. Many means have been proposed and some are in use for preventing this shock. In some of these constructions, sufiicient clearance is provided so that the dipper and stick assembly can move beyond the line of pull of the hoisting line. The amount of clearance which can be provided in this fashion Without curtailing the eifectiveness of the machine for digging is limited and the difficulty usually encounteredin such means lies in the fact that the dipper and stick assembly is carried by inertia, at'times, beyond the line of pull of the hoisting line and the limited clearance provided is of no use in preventing a violent and destructive engagement of the parts. In other constructions collision of the parts is not prevented but is rather, lessened or minimized by various forms of shock absorbing buffers. The buffers employed in these constructions are composed of-resilient material and unusually heavy shocks exceed the protecting power of these buffers when they are made soft enough to protect against smaller and more frequent shocks. Real protection of the machine against every contingency cannot be provided by the use of resilient buffers.

By means of this invention, restraint metered to the magnitude of the shock to be resisted is provided by utilizing the tension in the hoisting line to produce the restraint.

When the hoist- H motion is restrained by means which engage the The magni-' hoisting line and deflect the same. tude of this restraint is related to the tension in the hoistingline and in view of the fact that the violence of the outward movement of the dipper and stick assembly is also directly related to the tension in the hoisting line, in fact caused thereby, the dipper and stick assembly comes to a rest with respect to the boom at a balance point. Upon reference to the accompanying drawings and the explanation that follows, the construction of the machine of this invention and the manner in which the foregoing and: other advantages are obtained, will be quite apparent.

In the accompanying drawings, Fig. 1 shows a side view of a pull shovel embodying this invention;

Fig. 2 is a diagrammatic showing in perspective of a portion of the rigging of the hoisting line;

Fig. 3 is a side view of the outer portion of the boom and the'dipper and stick assembly, showing the latter .pulled to the extreme inner position;

Fig. 4 is a side view of the-outer portion of the boom and the dipper andstick assembly showing the latterin full lines in an extended position and in dotted lines in an intermediate position;

Fig. 5 is a front view of the winding drum used in controlling the hoisting line;

Fig. 6 is a sideview of another formof the machine of this invention;

Fig. 7 is a side view of another simplified form of the machine of this invention.

The machine shown in Fig. 1 is mounted upon a conventional rotatingv base crane body I. Em-

ployed in the construction are the mast 2, the

Fig. 2 toward the outer end of the boom. Hoisting line 5 passes the guiding member I3 mounted on the tip of the boom and is then bent about the heel sheave l4 mounted upon the rear of the guiding member l3 and the bearing sheave |5 to an anchorage IE on the lower side of the boom 3 which anchorage is spaced 2. short distance from the dipper stick pivot II. The digging line 6 extends from the winding drum I!) over the guide sheaves 2|] and 2| mounted on the boom and from there to a padlock sheave 22 pivotally secured to the dipper and from thence to a mounting guide directly behind guide sheave 2| and not shown to an anchorage 23 shown in dotted lines on the boom.

By operating winding drum 1 to pay out hoisting line 5 and by operating winding drum l9 to draw in the digging line 6, the dipper and stick assembly 4 may be moved from the position shown in Fig. 1 through a series of intermediate positions such as is shown in dotted lines in Fig. 4 to the position shown in Fig. 3. By holding winding drum I 9 fast and by operating winding drum 1 to take in the hoisting line 5, the entire boom and dipper may be elevated and by combinations of these manipulations, a wide range of excavating movements may be executed including both the loading and the discharging of the dipper.

In forming an excavation of maximum depth the dipper l8 and stick 4 may be extended as shown in Fig. 1, and in this position digging line 6 is'ordinarily permittedfor a moment to be slack. In this condition the moment imposed upon the dipper stick assembly by the hoisting line 5 urges the dipper stick assembly to move toward the outer end of the boom and. to close with it. This moment is small due to the short lever arm upon which it is applied, but this moment is large compared to the rather smaller opposing tendency imposed by gravity when the machine is in this position. The hoisting line 5, however, is brought to an anchorage l6 beneath the boom and passes under tension over the bearing sheave l5. As shown in Fig. 1 the hoisting line 5 is deflected by the bearing sheave |5. This deflection is the measure of a new moment which opposes movement of the dipper and stick assembly toward the boom. It will be seen that in this condition there are two opposing moments, bothborn'of the tension in the hoisting line 5. It-will also be apparent that due to the short spacing of anchorage l6 and guide sheave I3, the moment opposing the upward movement will increase far more rapidly than the moment urging the upward movement. Therefore, regardless of the degree to which the tension in hoisting line 5 is increased, there is a limiting position of the dipper and stick assembly with respect to the boom, in which position the dipper and stick assembly will come to a state of rest The provision of spring or resilient buffers to prevent shock is therefore unnecessary. However, if desired, such buffers can be employed in conjunction with this invention and will find a limited usefulness therein.

Another important advantage of the machine of this invention resides in the property of the device to yield to certain very violent forces without destruction of the machine. It is possible to wind the hoisting line 5 of the machine of this invention as rapidly as desired and upon the completion of the outer movement of the dipper stick assembly the same is brought to rest without destructive effect through the functioning of certain elements of the machine which are thoroughly capable of absorbing the energy released. Should the dipper stick assembly be swung outwardly with considerable speed to the position shown in Fig. 4, the kinetic energy of this outward movement must be absorbed when the dipper stick assembly is brought to rest. This is accomplished .in the machine of this invention because the deflection of the hoisting line 5 by the bearing sheave |5 calls for a lengthening of the cable. With cables commonly employed, the strength is so great that an enormous force would be required to stretch the cable enough to provide this necessary lengthening. Before such an extreme force becomes established a slipping of the hoisting brake 24 shown in Fig. 5 or hoisting drum driving clutch 25 actually occurs and absorbs the released energy. The brake 24 and clutch 25 are both designed to absorb energy and the dipper stick assembly is brought to rest thereby without destructive action on any part of the 7 machine.

Referring to Fig. 4 the boom end assembly may be considered as being composed of a movable dipper l8, a stick 4 pivotally connected to the boom 3, a digging line 6 for causing inward movements, and a'hoisting line 5 for causing outward movements and an indistinguishable portion of the hoisting line 5 acting as a sort of bridle. A construction embodying this invention which shows that the bridle portion of the hoisting line may sometimes be a more or less distinct element is shown in Fig. 6. In this figure is shown a dipper l8 secured to a stick 4, the latter being pivotally mounted on the boom 3' at pivot l1. 1

Pivotally mounted on the dipper I8 is the bell crank 3|). Hoisting line 5 is attached to the outer arm of bell crank 30 and passes over the guide member l3 and from there to an appropriate winding drum. Secured to the boom at anchorage It and extending to the inner arm of the bell crank 35 is the bridle line 3|. The operation of this form of the machine of this invention is exactly similar to the form shown in Fig. 4. For example in bringing the dipper and stick assembly to an extended position, a restraining sheave l5 engages the bridle line 3| deflecting the same. The tension in the bridle line 3|, however, is caused by tension in hoisting line 5 and the' restraint caused thereby is'metered to the tension in the hoisting line. The bridle line 3| may however be considered as no more than an extended portion of the hoisting line 5'.

In the forms described herein, the point of engagement of the hoisting line 5 or 5 with the dipper I8 or I8 is displaced from the pivot H or IT, a distance considerably greater than the displacement ofguide members |3 or l3. Upon extension of the dipper, the bridle line 3| or bridle portion of hoisting line 5 extends beyond the guiding member l3 or |3' on the tip of the boom as shown in Figure 4. Further outward movement of the dipper and stick assembly produces a second deflection in the bridle at the guide member I3. vides an additional restraint upon the outward movement of the dipper and stick assembly and comes into play in effecting the control of exceptionally severe outward movements.

In Fig. 7 is shown a simplified form of the machine of this invention. In this construction, a dipper I8" mounted upon a dipper stick 4 is dependently pivoted at pivot H" from boom 3". Boom 3" is provided at its outer extremity with guide sheave I3". Hoisting line 5" passes about a heel sheave |4" mounted on the dipper l8" and then passes to an anchorage it which in this construction, is secured to the dipper stick 4". As shown in Fig. 7, the bridle portion of hoisting line 5" is deflected by guide member This second deflection pro ened. However, the hoisting line 5 may connect the boom end assembly'directly with the winding means and operate successfully in this man ner.

Hereafter in the claims the heel sheave M or bell crank 30 or any equivalent means will be referred to as a hoist mounting.

We desire it to be understood that this invention is not to be limited to any particular form-or arrangement of parts except in so far as such limitations are included in the cia lns.

What we'claim as ourinvention is:

1. In an excavating machine, the combination with a boom and a dipper and stick assembly connected to said boom and movable with respect thereto, of a hoisting line connected to said dipper and stick assembly, and means adapted to engage said hoisting line when the dipper stick is brought into an outwardly extended predetermined position with relation to said boom, whereby said hoisting line will serve to absorb shocks caused by the relative movement of said boom :and dipper and stick assembly.

2.In an excavating machine, the combination with a boom and a dipper and stick assembly .connected'to said boom and movable into substantial alignment therewith, of ahoisting line connected with said dipper and stick assembly, and means-adapted to engage said hoisting line when the dipper and stick assembly is brought into substantial alignment with said boom, whereby said hoisting line will serve to absorb shocks caused by the relative movement of said boom and dipper and stick assembly.

3. The boom end assembly of an improved pull shovel which comprises a boom, a dipper and stick assembly pivotally mounted thereon, a hoisting line engaging said dipper and stick assembly, a bridle line tensioned by said hoisting line, connecting said boom to said dipper and stick assembly, means mounted upon said dipper and stick assembly for deflecting said bridle line when said dipper and stick assembly is moved to extended position, and a digging line engaging the inner side of said dipper and stick assembly.

4. The boom end assembly of an improved pull shovel which comprises a boom, a dipper and stick assembly pivotally mounted thereon, a hoist mounting on the heel of said dipper, a hoisting line engaging said hoist mounting, a bridle line also engaging said hoist mounting and anchored adjacent said pivot on the boom, means mounted upon said dipper and stick assembly for deflecting said bridle line when said dipper and stick assembly is moved to extended position, and a digging line engaging the inner side of said dipper and stick assembly.

5. The boom end assembly of an improved pull shovel which comprises a boom, a dipper and stick assembly pivotally mounted thereon, a hoist mounting on the heel of said dipper, a hoisting line engaging said hoist mounting, a bridle line also engaging said hoist mounting and anchored adjacent said pivot on the boom, means for defleeting said bridle use when said dipper and stick assembly is moved to extended position, and a digging lineengaging the inner side of said dipper and stick assembly.

6. The boom end assembly of an improved pull shovel which comprises a boom, a dipper and stick assembly pivotally mounted thereon, a hoist mounting on the heel of said dipper, a hoisting line engaging'the hoist mounting on said dipper and extending toan anchorage under said boom, 'means mounted upon said dipper and stick assembly for deflecting said hoisting line between the hoist mounting on the dipper and the anchorage under the boom when said dipper and stick assembly is moved to extended position, and a digging line engaging the inner side of said dipper-and stick assembly.

7. The boom end assembly of an improved pull shovel which comprises a boom, a dipper and stick assembly pivotally mounted thereon, a hoist mounting on the heel of. said dipper, a hoisting line engaging the hoist mounting on said dipper and extending to an anchorage under said boom, means for deflecting said hoisting line between the hoist mounting on the dipper and the anchorage under the boom when said dipper and stick assembly is moved to extended position, and a digging line engaging the inner side of said dipper and stick assembly.

8. The combination with a movable boom mounted upon a winch support, of a dipper and stick assembly dependently pivoted below the boom near the outer extremity thereof, a hoist mounting upon the dipper, a guide member mounted at the tip of the boom, a hoisting cable passing outwardly above the boom from the winch support through the guide member on the boom, thence about the hoist mounting on the dipper to an anchorage on the boom, a restraining means mounted upon the stick in position to deflect the hoisting line intermediate the hoist mounting and the anchorage when the dipper and stick assembly is extended, and a digging line passing outwardly from the winch support to engagement with the inner side of the dipper.

9. The combination of a movable boom mounted upon a winch support, winding means on the winch support including friction driving and arresting means, a dipper and stick assembly dependently pivoted below the boom near the outer extremity thereof, a hoist mounting upon the dipper, a guide member mounted at the tip of the boom, a hoisting cable passing outwardly above the boom from one of the winding means on the winch support through the guide member on the boom, thence about the hoist mounting to an anchorage, a restraining means mounted upon the stick in position to deflect the hoisting line intermediate the hoist mounting and the anchorage when the dipper and stick assembly is extended, and a digging line passing outwardly from the winch support to engagement with the inner side of the dipper.

10. The combination of a movable boom mounted upon a winch support, winding means on the winch support including friction driving and arresting means, a dipper and stick assembly dependently pivoted below the boom near the outer extremity thereof, a hoist mounting upon the dipper, a guide member mounted at the tip of the boom, a hoisting cable passing outwardly above the boom from one of the winding means on the winch support through the guide member on the boom, thence about the hoist mounting to an anchorage, a restraining means for deflecting the hoisting line intermediate the hoist mounting and the anchorage when the dipper and stick assembly is extended, anda digging line passing outwardly from the winch support to engagement with the inner side of the dipper.

11. An improved pull shovel which comprises a winch support, a movable boom mounted thereon, frictionally driven and arrested winding means mounted on the winch support, a dipper and stick assembly pivotally mounted on the boom, a hoisting line connected with one of the winding means on the winch support and engaging said dipper and stick assembly, a bridle line tensioned by said hoisting line connecting said boom to said dipper and stick assembly, means mounted upon said dipper and stick assembly for deflecting said bridle line when said dipper and stick assembly is moved to extended position, and a digging line engaging the inner side of said dipper and stick assembiy.

12. The combination of a movable boom mounted upon a winch support having a mast, a dipper and stick assembly pivotally mounted on the boom, a heel sheave mounted upon the dipper, a guide member mounted at the tip of the boom, a lifting sheave mounted near the mid point of the boom, a hoisting cable passing from the winch support over the mast, about the lifting sheave back to the winch support, again over the mast, then through the guide member on the boom, thence about the heel sheave on the dipper to an anchorage on the boom, a restraining sheave mounted upon the stick in position to deflect the hoisting line intermediate the heel sheave and the anchorage when the dipper and stick assembly is extended, and a digging line passing outwardly from the winch support to engagement with the inner side of. the dipper.

13. A boom end assembly of an improved pull shovel which comprises a boom, a dipper and stick assembly pivotally mounted thereon, a hoist mounting on the heel of said dipper, a hoisting line engaging the hoist mounting and extending to an anchorage under said boom, a

guiding means mounted upon said boom to deboo-m, a dipper and stick assembly pivotally dependent from the boom near the extremity thereof, a guiding member mounted upon the extremity of the boom, a hoist mounting upon said dipper and disposed beyond said guiding member when said dipper is in an outwardly projected position, a hoisting line engaging said hoist mounting and anchored inwardly of the outer end of said boom with a portion between its anchorage and said hoisting mounting movable into contact with said guiding member to check the movement of said dipper and stick assembly when said assembly is moved to extended position substantially lengthwise of the boom and away from the pivotal mounting thereof.

15. A boom end assembly of an improved pull shovel which comprises, a boom, a dipper and stick assembly pivotally dependent from the boom near the extremity thereof, a guiding member mounted upon the extremity of the boom, a hoist mounting upon said dipper, a hoisting line engaging said'hoist mounting and anchored to the dipper stick in position to be deflected by said guiding member when said dipper and dipper stick assembly is moved to extended position.

PAUL BURKE.

ARTHUR ORLOFF. 

